ICL7667 cpa, ua7810c help

I am new to circuitry ( dont roll your eyes yet). I am having some problems with voltage drop.

I am trying to get 36 10V pwm outputs using 18 7667's to control a bunch of meanwil drivers ( P model). I already use this setup for 4 drivers and it works fine.

ua7810
http://download.siliconexpert.com/pd...ual/ua7805.pdf

I am using a UA7810c to drop my voltage down to 10v, then feeding the 7667's with that.
I have tried to creat a PCB with one UA7810 and feed all 18 of the 7667's with that but the voltage drops to ~4v. So I came up with the idea of using 18 UA7810( one for each 7667).

So I got out my breadboard.

  1. I hooked up one ua7810c and supplied it with a 18.93v input. I then hooked up one 7667. The output voltage on the ua7810 is ~9.75v.
  2. So I got another ua7810c, also supplied it with the 18.93V supply. The output of the first one dropped down to 9.57v but the input of the first one is still 18.93v. The second UA7810 has an output of 9.66v.
  3. I hook a 7667 up to the second ua7810 and the output voltage of the first one ped down to 9.35v, the second one dropped to 9.6v and the input stays at 18.93.

and so on.

This is a 18.5v 3.5a power supply. I really don’t know what I am missing. It may be as simple as a resister but this is all very new to me.

If there is a better way to do this. I have read about using 2n2222 but also read this is more for the D model.

Thank you for any assistance you can provide.

( Ok you can roll your eyes now) :slight_smile:
Mike

You have got all the right capacitors in place for the 7810's?

I did not. But now I do and it works perfect. Thank you, I figured I was missing something. Still new to all this. I put a .1uF before the regulator, and a .22uF and .1uF after it. I am now getting 10v for all the 7667's.